/*      $NetBSD: win32select.c,v 1.6 2024/08/18 20:47:21 christos Exp $ */

/*
* Copyright 2007-2012 Niels Provos and Nick Mathewson
* Copyright 2000-2007 Niels Provos <[email protected]>
* Copyright 2003 Michael A. Davis <[email protected]>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
*    derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "event2/event-config.h"
#include "evconfig-private.h"

#ifdef _WIN32

#include <winsock2.h>
#include <windows.h>
#include <sys/types.h>
#include <sys/queue.h>
#include <limits.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#include "event2/util.h"
#include "util-internal.h"
#include "log-internal.h"
#include "event2/event.h"
#include "event-internal.h"
#include "evmap-internal.h"
#include "event2/thread.h"
#include "evthread-internal.h"
#include "time-internal.h"

#define XFREE(ptr) do { if (ptr) mm_free(ptr); } while (0)

extern struct event_list timequeue;
extern struct event_list addqueue;

struct win_fd_set {
       unsigned int fd_count;
       SOCKET fd_array[1];
};

/* MSDN says this is required to handle SIGFPE */
volatile double SIGFPE_REQ = 0.0f;

struct idx_info {
       int read_pos_plus1;
       int write_pos_plus1;
};

struct win32op {
       unsigned num_fds_in_fd_sets;
       int resize_out_sets;
       struct win_fd_set *readset_in;
       struct win_fd_set *writeset_in;
       struct win_fd_set *readset_out;
       struct win_fd_set *writeset_out;
       struct win_fd_set *exset_out;
       unsigned signals_are_broken : 1;
};

static void *win32_init(struct event_base *);
static int win32_add(struct event_base *, evutil_socket_t, short old, short events, void *idx_);
static int win32_del(struct event_base *, evutil_socket_t, short old, short events, void *idx_);
static int win32_dispatch(struct event_base *base, struct timeval *);
static void win32_dealloc(struct event_base *);

struct eventop win32ops = {
       "win32",
       win32_init,
       win32_add,
       win32_del,
       win32_dispatch,
       win32_dealloc,
       0, /* doesn't need reinit */
       0, /* No features supported. */
       sizeof(struct idx_info),
};

#define FD_SET_ALLOC_SIZE(n) ((sizeof(struct win_fd_set) + ((n)-1)*sizeof(SOCKET)))

static int
grow_fd_sets(struct win32op *op, unsigned new_num_fds)
{
       size_t size;

       EVUTIL_ASSERT(new_num_fds >= op->readset_in->fd_count &&
              new_num_fds >= op->writeset_in->fd_count);
       EVUTIL_ASSERT(new_num_fds >= 1);

       size = FD_SET_ALLOC_SIZE(new_num_fds);
       if (!(op->readset_in = mm_realloc(op->readset_in, size)))
               return (-1);
       if (!(op->writeset_in = mm_realloc(op->writeset_in, size)))
               return (-1);
       op->resize_out_sets = 1;
       op->num_fds_in_fd_sets = new_num_fds;
       return (0);
}

static int
do_fd_set(struct win32op *op, struct idx_info *ent, evutil_socket_t s, int read)
{
       struct win_fd_set *set = read ? op->readset_in : op->writeset_in;
       if (read) {
               if (ent->read_pos_plus1 > 0)
                       return (0);
       } else {
               if (ent->write_pos_plus1 > 0)
                       return (0);
       }
       if (set->fd_count == op->num_fds_in_fd_sets) {
               if (grow_fd_sets(op, op->num_fds_in_fd_sets*2))
                       return (-1);
               /* set pointer will have changed and needs reiniting! */
               set = read ? op->readset_in : op->writeset_in;
       }
       set->fd_array[set->fd_count] = s;
       if (read)
               ent->read_pos_plus1 = set->fd_count+1;
       else
               ent->write_pos_plus1 = set->fd_count+1;
       return (set->fd_count++);
}

static int
do_fd_clear(struct event_base *base,
                       struct win32op *op, struct idx_info *ent, int read)
{
       int i;
       struct win_fd_set *set = read ? op->readset_in : op->writeset_in;
       if (read) {
               i = ent->read_pos_plus1 - 1;
               ent->read_pos_plus1 = 0;
       } else {
               i = ent->write_pos_plus1 - 1;
               ent->write_pos_plus1 = 0;
       }
       if (i < 0)
               return (0);
       if (--set->fd_count != (unsigned)i) {
               struct idx_info *ent2;
               SOCKET s2;
               s2 = set->fd_array[i] = set->fd_array[set->fd_count];

               ent2 = evmap_io_get_fdinfo_(&base->io, s2);

               if (!ent2) /* This indicates a bug. */
                       return (0);
               if (read)
                       ent2->read_pos_plus1 = i+1;
               else
                       ent2->write_pos_plus1 = i+1;
       }
       return (0);
}

#define NEVENT 32
void *
win32_init(struct event_base *base)
{
       struct win32op *winop;
       size_t size;
       if (!(winop = mm_calloc(1, sizeof(struct win32op))))
               return NULL;
       winop->num_fds_in_fd_sets = NEVENT;
       size = FD_SET_ALLOC_SIZE(NEVENT);
       if (!(winop->readset_in = mm_malloc(size)))
               goto err;
       if (!(winop->writeset_in = mm_malloc(size)))
               goto err;
       if (!(winop->readset_out = mm_malloc(size)))
               goto err;
       if (!(winop->writeset_out = mm_malloc(size)))
               goto err;
       if (!(winop->exset_out = mm_malloc(size)))
               goto err;
       winop->readset_in->fd_count = winop->writeset_in->fd_count = 0;
       winop->readset_out->fd_count = winop->writeset_out->fd_count
               = winop->exset_out->fd_count = 0;

       if (evsig_init_(base) < 0)
               winop->signals_are_broken = 1;

       evutil_weakrand_seed_(&base->weakrand_seed, 0);

       return (winop);
err:
       XFREE(winop->readset_in);
       XFREE(winop->writeset_in);
       XFREE(winop->readset_out);
       XFREE(winop->writeset_out);
       XFREE(winop->exset_out);
       XFREE(winop);
       return (NULL);
}

int
win32_add(struct event_base *base, evutil_socket_t fd,
                        short old, short events, void *idx_)
{
       struct win32op *win32op = base->evbase;
       struct idx_info *idx = idx_;

       if ((events & EV_SIGNAL) && win32op->signals_are_broken)
               return (-1);

       if (!(events & (EV_READ|EV_WRITE)))
               return (0);

       event_debug(("%s: adding event for %d", __func__, (int)fd));
       if (events & EV_READ) {
               if (do_fd_set(win32op, idx, fd, 1)<0)
                       return (-1);
       }
       if (events & EV_WRITE) {
               if (do_fd_set(win32op, idx, fd, 0)<0)
                       return (-1);
       }
       return (0);
}

int
win32_del(struct event_base *base, evutil_socket_t fd, short old, short events,
                 void *idx_)
{
       struct win32op *win32op = base->evbase;
       struct idx_info *idx = idx_;

       event_debug(("%s: Removing event for "EV_SOCK_FMT,
               __func__, EV_SOCK_ARG(fd)));
       if (events & EV_READ)
               do_fd_clear(base, win32op, idx, 1);
       if (events & EV_WRITE)
               do_fd_clear(base, win32op, idx, 0);

       return 0;
}

static void
fd_set_copy(struct win_fd_set *out, const struct win_fd_set *in)
{
       out->fd_count = in->fd_count;
       memcpy(out->fd_array, in->fd_array, in->fd_count * (sizeof(SOCKET)));
}

/*
 static void dump_fd_set(struct win_fd_set *s)
 {
 unsigned int i;
 printf("[ ");
 for(i=0;i<s->fd_count;++i)
 printf("%d ",(int)s->fd_array[i]);
 printf("]\n");
 }
*/

int
win32_dispatch(struct event_base *base, struct timeval *tv)
{
       struct win32op *win32op = base->evbase;
       int res = 0;
       unsigned j, i;
       int fd_count;
       SOCKET s;

       if (win32op->resize_out_sets) {
               size_t size = FD_SET_ALLOC_SIZE(win32op->num_fds_in_fd_sets);
               if (!(win32op->readset_out = mm_realloc(win32op->readset_out, size)))
                       return (-1);
               if (!(win32op->exset_out = mm_realloc(win32op->exset_out, size)))
                       return (-1);
               if (!(win32op->writeset_out = mm_realloc(win32op->writeset_out, size)))
                       return (-1);
               win32op->resize_out_sets = 0;
       }

       fd_set_copy(win32op->readset_out, win32op->readset_in);
       fd_set_copy(win32op->exset_out, win32op->writeset_in);
       fd_set_copy(win32op->writeset_out, win32op->writeset_in);

       fd_count =
           (win32op->readset_out->fd_count > win32op->writeset_out->fd_count) ?
           win32op->readset_out->fd_count : win32op->writeset_out->fd_count;

       if (!fd_count) {
               long msec = tv ? evutil_tv_to_msec_(tv) : LONG_MAX;
               /* Sleep's DWORD argument is unsigned long */
               if (msec < 0)
                       msec = LONG_MAX;
               /* Windows doesn't like you to call select() with no sockets */
               Sleep(msec);
               return (0);
       }

       EVBASE_RELEASE_LOCK(base, th_base_lock);

       res = select(fd_count,
                    (struct fd_set*)win32op->readset_out,
                    (struct fd_set*)win32op->writeset_out,
                    (struct fd_set*)win32op->exset_out, tv);

       EVBASE_ACQUIRE_LOCK(base, th_base_lock);

       event_debug(("%s: select returned %d", __func__, res));

       if (res <= 0) {
               event_debug(("%s: %s", __func__,
                   evutil_socket_error_to_string(EVUTIL_SOCKET_ERROR())));
               return res;
       }

       if (win32op->readset_out->fd_count) {
               i = evutil_weakrand_range_(&base->weakrand_seed,
                   win32op->readset_out->fd_count);
               for (j=0; j<win32op->readset_out->fd_count; ++j) {
                       if (++i >= win32op->readset_out->fd_count)
                               i = 0;
                       s = win32op->readset_out->fd_array[i];
                       evmap_io_active_(base, s, EV_READ);
               }
       }
       if (win32op->exset_out->fd_count) {
               i = evutil_weakrand_range_(&base->weakrand_seed,
                   win32op->exset_out->fd_count);
               for (j=0; j<win32op->exset_out->fd_count; ++j) {
                       if (++i >= win32op->exset_out->fd_count)
                               i = 0;
                       s = win32op->exset_out->fd_array[i];
                       evmap_io_active_(base, s, EV_WRITE);
               }
       }
       if (win32op->writeset_out->fd_count) {
               i = evutil_weakrand_range_(&base->weakrand_seed,
                   win32op->writeset_out->fd_count);
               for (j=0; j<win32op->writeset_out->fd_count; ++j) {
                       if (++i >= win32op->writeset_out->fd_count)
                               i = 0;
                       s = win32op->writeset_out->fd_array[i];
                       evmap_io_active_(base, s, EV_WRITE);
               }
       }
       return (0);
}

void
win32_dealloc(struct event_base *base)
{
       struct win32op *win32op = base->evbase;

       evsig_dealloc_(base);
       if (win32op->readset_in)
               mm_free(win32op->readset_in);
       if (win32op->writeset_in)
               mm_free(win32op->writeset_in);
       if (win32op->readset_out)
               mm_free(win32op->readset_out);
       if (win32op->writeset_out)
               mm_free(win32op->writeset_out);
       if (win32op->exset_out)
               mm_free(win32op->exset_out);
       /* XXXXX free the tree. */

       memset(win32op, 0, sizeof(*win32op));
       mm_free(win32op);
}

#endif

You are viewing proxied material from ftp.icm.edu.pl. The copyright of proxied material belongs to its original authors. Any comments or complaints in relation to proxied material should be directed to the original authors of the content concerned. Please see the disclaimer for more details.